In recent years, the read heads of magnetoresistive devices and recording bits on magnetic recording media have become progressively smaller, and as a result, the recording density of stored data has increased. Smaller recording bits generate smaller magnetic flux and smaller output signals, which increase the sensitivity requirements of the read head. A scissor type sensor, which has two free ferromagnetic layers being coupled in anti-parallel directions relative to each other, has been proposed to further improve the sensitivity of the read head. One difficulty encountered is that when various stresses, including external magnetic fields and heat, are applied to read heads with scissor type sensors, bias magnetization reversal often occurs and causes hysteresis in the transfer curve. These complications have limited the practical application of scissor type sensors in conventional magnetoresistive devices.